Combiners come in multiple ways yes. personal progression, multiple diffrent items and personal, and both for shared progression.
As to the tools then
Shared (one per land or alliance but still shared)
reliability depends on the actual amount of possible outcomes but for getting the same thing out that you mined 10%
getting into the who can pick up, cooldown, transferable or not and such i'll not go.

If the entire multiverse actually resets back to the state that was the beginning then i don't think there is any way.
if it's somekind of localized event then there are options i guess. You just have to find the limits of the localization first.

Ave,
A idea i had today.
All the combiners have resources left in them by players gone or players who don't care to finish the amount needed and so on.
So i was thinking that why not make a tool to mine the combiners. Not with particular accuracy on who's stuff get's removed from there and what is the end result (bulb of toxic plants. toxic plants, impotent flask of toxic plants for example the one combiner).
Offering this idea for few reasons,
1)Otherwise the combiners will end up being filled with stupid amount of stuff for no good.
2)It's interesting/fun
3)depending on how it's implemented might allow even to sabotage someone(s)
Miq

Ave,
I have totally forgotten this. I hope everyone who got some replanted the cucumbers :).
As to the reward. Then i'm unaware that i have been considered worthy and also have not got any WP for it.
Miq